“If evolution and the survival of the fittest be true at all, the destruction of prey and of human rivals must have been among the most important. . . . It is just because human bloodthirstiness is such a primitive part of us that it is so hard to eradicate, especially when a fight or a hunt is promised as part of the fun.” IfsHumansHas BeensImportantHardFightingFunEvolutionSurvivalDestructionBeing TruePrimitiveHuntsPreyRivalsSurvival Of The Fittest Book:The Principles of Psychology, Vol. 2 Source: The Principles of Psychology, Vol. 2